What to do if you're trapped in a car in a flash flood

The devastation left behind by Hurricane Harvey in Texas and Louisiana won’t soon be forgotten.

And the catastrophic flooding caused by the historic storm brings to the fore some important safety practices motorists need to remember in the event your find yourself trapped in your car by the rising waters of a flash flood.

Here are the do’s and don’ts for drivers caught in the deluge:

Do…

Stay calm. This may seem easier said than done, but you'll need your wits about you.

Turn on your headlights and hazard lights to make it easier for emergency personnel to see you.

Unbuckle your seat belt.

Unlock your doors.

Take off jackets and outer clothing.

Lower your window slowly. Most electric windows should work unless the car is completely submerged in water.

If the windows won’t open, you'll have to use a door. But you won't be able to open a door until the water pressure is equalized between the outside and the inside of the car. This means you'll have to wait for water to enter the car and fill up to about your neck level (this sounds terrifying, but this is the only way the doors will open).

Once free, swim to safety and call 911.

Don't…

Panic.

Waste energy trying to open the doors, as water pressure will keep them from budging (wait for the pressure to equalize).

Try to save your possessions.

Break windows to get out, unless as a last resort. If pressure has not equalized, glass will explode inward toward you.

Stay with your car once you’ve escaped. Get to high ground.

Return to your car if you think the water is going down. Water levels could rise without warning. Just have it towed later.

While some victims are caught without warning by the rushing waters of a flash flood, too often motorists make the dangerous decision to drive through floodwaters of unknown depth.

Remember, it’s easy to misjudge the depth of water, especially at night. It takes just 6 inches of water to reach the bottom of most passenger vehicles and cause loss of control. Even a foot can carry many vehicles away — while 2 feet can sweep away a pickup or SUV — and you with it.